666667889 has 8 divisors (see below), whose sum is σ = 678063360. Its totient is φ = 655315056.

The previous prime is 666667861. The next prime is 666667907. The reversal of 666667889 is 988766666.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 666667889 - 2⁸ = 666667633 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (666667819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21707 + ... + 42479.

It is an arithmetic number, because the mean of its divisors is an integer number (84757920).

Almost surely, 2^666667889 is an apocalyptic number.

It is an amenable number.

666667889 is a deficient number, since it is larger than the sum of its proper divisors (11395471).

666667889 is a wasteful number, since it uses less digits than its factorization.

666667889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21319.

The product of its digits is 31352832, while the sum is 62.

The square root of 666667889 is about 25819.9126450885. The cubic root of 666667889 is about 873.5809986392.

The spelling of 666667889 in words is "six hundred sixty-six million, six hundred sixty-seven thousand, eight hundred eighty-nine".